Title: Prototype Prestressed Beam Justifies Walnut Lane Bridge Design
Author(s): Gustave Magnel
Publication: Journal Proceedings
Appears on pages(s): 301-316
Keywords: no keywords
The tests made on prestressed concrete beam of 154 ft 8 in. span, identical to the beams of the main span of the Walnut Lane Bridge in Philidelphia, more than justified the adoption of prestressed concrete for the bridge. The test methods and results are described. The test beam exhitbited a safety factor against cracking of about 2, which would be far lower for a reinforced concrete beam. The factor of safety against complete failure was about the same as for reinforced concrete while the deflection was less. It is possible to use prestressed concrete for beams where structural steel can not be used due to excessive deflection. The tests proved that the Walnut Lane Bridge will have an exceptional degree of safety with less weight and greater durablity than would be possible with reinforced concrete, as well as being considerably cheaper than the conventional solution.